Comparison of various pupil dilatation methods for phacoemulsification in eyes with a small pupil secondary to pseudoexfoliation

Abstract

Purpose To compare 4 methods for intraoperative pupil dilatation in eyes with pseudoexfoliation syndrome and insufficient pupil size during phacoemulsification. Design Prospective, randomized, comparative, interventional case series. Participants Forty eyes of 40 patients with pseudoexfoliation and maximally dilated pupil size smaller than 3.5 mm. Intervention Mechanical pupil dilatation with iris-retractor hooks (group I), polymethyl methacrylate (PMMA) pupil dilator-ring (Morcher, Stuttgart, Germany) (group II), Beehler pupil dilator (group III), and bimanual stretching (group IV). Main outcome measures Performance (pupil size achieved), complications, and added surgical time. Results The mean pupil sizes achieved with the PMMA pupil-dilator ring, Beehler pupil dilator, and bimanual stretching were 5.9±0.6 mm, 5.5±0.8 mm, and 4.9±0.7 mm, respectively. A square-shaped pupil was achieved with iris-retractor hooks, and the mean size of the largest circle that can fit in this square was 5.6±0.6 mm. There were no statistically significant differences in the postdilatation pupil sizes between the 4 study groups ( P>0.05). Apart from self-limited intraoperative hemorrhage from pupil margin, iris sphincter rupture was the only observed complication related to mechanical pupil dilatation. This occurred in 4 eyes in groups I and III, 3 eyes in group IV, and 1 eye in group II ( P>0.05). The mean added surgical time for placement of iris-retractor hooks and for implantation of a PMMA pupil-dilator ring was 297±51 and 176±54 seconds, respectively. The additional time required for pupil dilatation with the Beehler pupil dilator and bimanual stretching was 65±8 and 55±10 seconds, respectively. The time needed for pupil dilatation in groups I and II is significantly longer than that in groups III and IV ( P<0.001). Conclusions All 4 methods used in this study were effective procedures for the mechanical dilatation of small pupils secondary to pseudoexfoliation syndrome. Iris-retractor hooks and the PMMA pupil-dilator ring are the most time-consuming techniques but have the advantage of a stable pupil size throughout the surgery. The PMMA pupil-dilator ring causes the least iris trauma. The Beehler pupil dilator and bimanual stretching technique were the least time-consuming methods for mechanical pupil dilatation.